OTS-167 is a maternal embryonic leucine zipper kinase (MELK) inhibitor which demonstrated antitumor properties in laboratory tests. It is being developed as an anti-cancer drug. The compound has been shown to suppress the growth of breast, lung, pancreatic and prostate cancer cells that express high levels of the MELK protein. OTS167 reached phase II clinical trials in patients with AML, ALL, advanced MDSs, advanced MPNs, or advanced CML and phase I in patients with breast cancer.

CPI-0610 is a small molecule inhibitor of the Bromodomain and Extra-Terminal (BET) family of proteins, with potential antineoplastic activity. Upon administration, the BET inhibitor CPI-0610 binds to the acetylated lysine recognition motifs on the bromodomain of BET proteins, thereby preventing the interaction between the BET proteins and acetylated histone peptides. This disrupts chromatin remodeling and gene expression. Prevention of the expression of certain growth-promoting genes may lead to an inhibition of tumor cell growth. CPI-0610 is currently being evaluated in three Phase 1 clinical trials in the U.S.

Pexmetinib (ARRY-614) is a potent, orally bioavailable, dual p38 MAPK/Tie-2 inhibitor with potential antineoplastic, anti-inflammatory and antiangiogenic activities. Pexmetinib inhibited leukemic proliferation, prevented activation of downstream effector kinases and abrogated the effects of TNF-alpha on healthy hematopoietic stem cells. In ex vivo stimulated human whole blood, LPS-induced cytokines was inhibited by Pexmetinib with an IC50 value ranging from 50-120 nM. ARRY-614 inhibited the release of IL-6 from SEA- or LPS-challenged mice with an ED50 value less than 10 mg/kg. Combining Pexmetinib with lenalidomide inhibited both pro-inflammatory cytokines and tumor growth in vivo with higher potency, compared with either agent alone. In dose escalation or expansion cohorts, treatment with Pexmetinib either once daily or twice daily was applied to forty-five patients. Pexmetinib reduced the levels of circulating biomarkers and the p38 MAPK activation of bone marrow.

Bryostatin 1 is a macrocyclic lactone which can be isolated from the marine bryozoan, Bugula neritina. The effects of bryostatin 1 are attributed to its ability to selectively modulate the activity of two of the three subgroups of protein kinase C (PKC) isozymes. PKC isozymes are divided into three subgroups which differ in their molecular structures and co-factor requirements: classical PKC (cPKC), novel PKC (nPKC), and atypical PKC (aPKC). Bryostatin-1 modulates nPKC activity independent of a Ca2+ signaling. It activates cPKC only when associated with Ca2+ signaling. And, aPKC activity is not sensitive to bryostatin-1 administration. Ca2+ signals play an important role in synaptic transmission and information processing which creates a biological environment where Bryostatin-1 possesses a unique action profile. Bryostatin-1 will not affect cPKC activity in neurons which are not functioning as an active part of the signaling processing circuit with significant Ca2+influx and intracellular Ca2+ release. Bryostatin 1 is in phase II clinical trials for investigation as an anticancer agent; specifically for treatment of metastatic or recurrent head and neck cancer, ovarian epithelial cancer that has not responded to previous chemotherapy, and myelodysplastic syndrome. Bryostatin 1 has also generated interest as an investigational compound for the treatment of Alzheimer's disease.

BVD-523 potently and selectively inhibits ERK1 and ERK2 kinases in a reversible, ATP-competitive fashion. Consistent with its mechanism of action, BVD-523 inhibits signal transduction, cell proliferation, and cell survival, most potently in cell lines bearing mutations that activate MAPK pathway signaling. Similarly, single-agent BVD-523 inhibits tumor growth in vivo in BRAF-mutant melanoma and colorectal xenografts as well as in KRAS-mutant colorectal and pancreatic models. BioMed Valley Discoveries is developing ulixertinib, a potent and selective small molecule inhibitor of ERK 1 and 2 kinases, as an oral treatment for cancers harbouring mutations in the MAPK signaling pathway. Phase I/II development of the drug for advanced cancers including, acute myeloid leukaemia and myelodysplastic syndromes is underway in the US. A phase I trial is underway in the US for pancreatic cancer.

Rigosertib sodium (ON 01910.Na) is a small molecule inhibitor of critical pathways important in the growth and survival of cancer cells, being developed by Onconova Therapeutics ("Onconova") for the treatment of hematologic malignancies and solid tumors. Rigosertib (ON-01910) is a non-ATP-competitive inhibitor of PLK1 with IC50 of 9 nM in a cell-free assay. It shows 30-fold greater selectivity against Plk2 and no activity to Plk3. Extensive Phase I and Phase II studies with rigosertib have been conducted at leading institutions in the U.S. and abroad in more than 450 patients with solid tumors and hematological cancers, including MDS and AML. MDS and AML are blood disorders widely recognized as difficult to manage, with limited therapeutic options available for patients, especially those with drug-resistant disease. The multi-site Phase III ONTIME trial in MDS patients is under a Special Protocol Assessment (SPA) from the U.S. FDA and is being supported by an award from the Therapeutics Acceleration Program (TAP) of the Leukemia and Lymphoma Society (LLS). FDA has granted Orphan Drug Designation for the use of rigosertib in MDS. The clinical program in solid tumors is also advancing with initiation of the Phase II/III combination ONTRAC trial (ON 01910.Na TRial in Patients with Advanced Pancreatic Cancer) and Phase II single agent trial in ovarian cancer. In Japan, SymBio is developing rigosertib for the treatment of refractory/relapsed HR-MDS (IV form) and first-line LR-MDS (oral form).

Pevonedistat (MLN4924), discovered by Millennium, is a small molecule inhibitor of the NEDD8-Activating Enzyme (NAE), a key component of the protein homeostasis pathway. MLN4924 is a mechanism-based inhibitor of NAE and creates a covalent NEDD8-MLN4924 adduct catalyzed by the enzyme. The NEDD8-MLN4924 adduct resembles NEDD8 adenylate, the first intermediate in the NAE reaction cycle, but cannot be further utilized in subsequent intraenzyme reactions. The stability of the NEDD8-MLN4924 adduct within the NAE active site blocks enzyme activity, thereby accounting for the potent inhibition of the NEDD8 pathway by MLN4924. This drug is in phase II clinical trial for the treatment acute myeloid leukemia, chronic myelomonocytic leukemia and myelodysplastic syndromes. In addition in phase I for treatment acute lymphoblastic leukemia. The ability of MLN4924 to cross the blood-brain barrier, its low toxicity, and clinical efficacy in other cancers suggests that this drug is an attractive treatment against glioblastomas.

APTO-253 is a novel small molecule that can induce expression of the genes that code for the Krüppel-like factor 4 (KLF4) master transcription factor and for the p21 cell cycle inhibitor protein, and can inhibit expression of the c-Myc oncogene, leading to cell cycle arrest and programmed cell death (apoptosis) in human-derived solid tumor and hematologic cancer cells. A Phase 1 study with APTO-253 was completed and demonstrated modest clinical activity in patients with colon cancer, acute leukemia, myelodysplastic syndrome, hematological malignancies and non-small cell lung cancers.

Pracinostat is a pan-histone deacetylase inhibitor being tested in phase II of clinical trials for the treatment of sarcoma, prostate cancer, acute myeloid leukemia, myelofibrosis, myelodysplastic syndrome. The drug was shown to be active in vitro on HCT116 and HL-60 cells.

CPI-613 is a lipoate derivative synthesized to be catalytically inert but to potentially mimic lipoate catalytic intermediates. The drug is in phase II of clinical trials for the treatment of Myelodysplastic syndromes; Pancreatic cancer; Small cell lung cancer; Solid tumors; Bile duct cancer; Acute Myeloid leukemia. The mechanism of CPI-613 action can be explained by (I) inhibition of tumor cell pyruvate dehydrogenase complex (PDC) through activation of pyruvate dehydrogenase kinases leading to inactivating phosphorylation of the E1alpha-subunit of PDC; and (II) inhibition of alpha-ketoglutarate dehydrogenase.